JPS6380471A - Nonaqueous electrolyte cell - Google Patents

Abstract

PURPOSE:To sharply improve a liquid leakage resistance property and a retention property by using a sealing material mainly composed of pitch and mixed with a specific quantity of spherical silicon resin fine powder as a sealing material. CONSTITUTION:A sealing material mainly composed of pitch and mixed with 5-20 weight % of spherical silicone resin fine powder is used as a sealing material. When such a filler closely fills the part 7, where a sealing ring 3 made of synthetic resin faces a cell casing 2, and the part 7', where the sealing ring 3 faces a sealing plate 1, said filler provides extremely good tightness to either of the sealing ring 3, the cell casing 2 and the sealing plate 1 and being insoluble in an electrolyte thus being able to fully hold gas-tightness of the sealing part.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention uses active light metals such as lithium, magnesium, and potassium as a negative electrode active material, and uses carbon fluoride.

A positive electrode active material consisting of manganese dioxide, copper oxide, etc.

The purpose of this invention is to significantly improve the leakage resistance and storage performance of non-aqueous electrolyte batteries using non-aqueous electrolytes.

BACKGROUND OF THE INVENTION Conventionally, batteries of this type have had drawbacks such as an increase in the rate of leakage, progression of self-discharge, and a considerable decrease in capacity after storage as the number of days after storage elapses after manufacture. These drawbacks are overwhelmingly due to imperfections in the sealing structure, and these drawbacks can be almost eliminated if the battery is completely sealed, whether it is a flat bicylindrical battery or a paper-shaped battery.

Various attempts have been made to completely seal batteries, but the above-mentioned drawbacks have not been completely eliminated. As an example, a flat non-aqueous electrolyte battery will be described. A conventional battery has a structure as shown in Figs. 1 and 2, and the case 2 is sealed with a sealing mold in a second
By bending as shown in the figure, the synthetic resin insulating ring 301 part and b part are deformed and compressed by 20 to 60%, and the sealing ring is sandwiched between the sealing plate 1 and the case 2. Furthermore, for the purpose of complete sealing, a polymeric sealing material 9 such as polybutene or polyisobutylene is applied or filled on the opposing portion 7 of the sealing ring and the positive electrode case and the opposing portion 7' of the sealing ring and the negative electrode sealing plate. Problems to be Solved by the Invention However, in this type of battery, propylene carbonate, dimethoxyethane, γ-butyrolactone, etc. are used alone or as a mixed solution, and lithium borofluoride or lithium perchlorate is dissolved in this solution. These are all volatile organic solvents, so the sealing material may gradually dissolve in the solvent, swell and soften during storage after battery manufacture. As a result, after long-term storage, the electrolytic solution leaked through the seal portions 7 and 7', resulting in extremely poor leakage resistance. In addition, the dissolution/swelling/softening phenomenon of the sealing material becomes more pronounced as it is stored at higher temperatures.
Store at 46°C, store at 60°C.

In general liquid leakage testing methods for flat batteries, such as high temperature-low temperature cycle tests, there are drawbacks in that the sealing material is pushed out of the battery and the leakage resistance performance is significantly deteriorated.

The present invention aims to provide a nonaqueous electrolyte battery that solves the above problems and has good leakage resistance and storage characteristics.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention replaces the conventional polymeric sealing material such as polybutene or polyisobutylene as a sealing material with pitch as a main component and a 6-20% %
The sealing material is a mixture of fine spherical silicone resin powder.

Function: If a sealing material containing this pitch as a main component and mixed with 5 to 20% by weight of spherical silicone resin fine powder is used, a non-aqueous electrolyte battery with good leakage resistance and storage characteristics can be provided.

Example Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1 and FIG. 2 showing an enlarged view of part A thereof,
Reference numeral 1 denotes a shallow dish-shaped sealing plate to which a negative electrode active material lithium 6 is crimped, and inside the container there is a separator 6 made of polypropylene and a molded positive electrode mixture containing fluorocarbon, manganese dioxide, copper oxide, etc. as a positive electrode active material. 4 is mounted, a non-aqueous electrolyte 8 containing propylene carbonate and dimethoxyethane as main components is sealed, a portion 7 where the sealing ring 3 and the dish-shaped positive electrode case 2 face each other, the sealing ring 3 and the sealing plate 1 A flexible and adhesive sealant 9& made of, for example, a mixture of pitch and fine spherical silicone resin powder is interposed in the opposing portion 7' of the negative electrode sealing plate 1 and the positive electrode case 2. A sealing ring 3 is inserted to completely seal it.

The mixture of pitch and spherical silicone resin fine powder according to the present invention can satisfy all of the following conditions for a sealant by setting an appropriate blending ratio.

(1) The sealing ring 3 and the positive electrode case 2 should not melt or swell or soften in the organic electrolyte during storage of the battery. (2) The sealing ring 3 and the positive electrode case 2 should not melt, soften, or deform in the synthetic resin insulation sealing ring 3. can be coated or filled without any gaps in the portion 7 where the sealing ring 3 and the negative electrode sealing plate 1 face each other. (3) The sealing ring 3, the positive electrode case 2, and the negative electrode sealing plate 1 must be firmly and liquid-tightly adhered to each other.

The pitch-based sealant containing 6 to 20% by weight of spherical silicone resin fine powder according to the present invention is more effective for non-aqueous electrolyte batteries than conventionally used sealants such as polybutene and polyisobutylene. It is extremely resistant to dissolution and does not swell even when it comes into contact with organic electrolytes used in applications such as organic electrolytes, etc. It also has the characteristics of not swelling even at high temperatures of 46°C to 60°C.
Compared to polybutene, polyisobutylene, etc., it has less fluidity and has excellent adhesion to metals, resins, etc., so it does not leak out of the battery and exhibits excellent leakage resistance.

FIG. 3 shows the results of a leakage test on batteries whose sealing parts were filled with a pitch-based sealant containing spherical silicone resin fine powder mixed in various proportions.

In addition, in this Figure 3, each sample is 200
(a) is a battery equipped with a pitch-based sealant mixed with spherical silicone resin fine powder (particle size 1 to 6μ) at room temperature.
Leakage rate after 0 days of storage, (b) 10 at 45°C for batteries with the same sealant as in body
Leakage rate after 0 days of storage, (0) is the high temperature (60
After conducting a cycle test (MIL, STD, 202D-106G) that repeats storage at low temperature (-10"C) and low temperature (-10"C) for 10 days, the leakage rate after being left at room temperature for 90 days, (d) is ( 1 at 60 °C for cells with the same encapsulant as &)
Leakage rate after 00 days of storage. As is clear from Figure 3, the leakage resistance is very good when the mixing ratio of the spherical silicone resin fine powder is in the range of 6 to 20% by weight; In the case of mixing less than 5% by weight and more than 20% by weight, both showed high leakage rates.

This is true in the pinch alone or in the range where the mixing ratio of spherical silicone resin fine powder is less than 6% by weight,
It has poor flexibility as a sealant, and has weak adhesion to the sealing ring, battery case, and sealing plate, and is easily peeled off. It is thought that the electrolyte leaks easily from the tank, leading to a high leakage rate.

On the other hand, if the mixing ratio is more than 20% by weight, the flexibility of the sealant and its adhesion to metals etc. will be good, but on the other hand, it will have fluidity at high temperatures, so the sealant will have good flexibility at 46°C or 60°C. When stored at such high temperatures, this sealant easily softens, flows, and flows out of the battery, rendering it no longer able to function as a sealant, resulting in a very high rate of battery leakage. .

Examples of mixtures having the above properties will be explained below.

Blown asphalt 1O-20 (temperature 25
Penetration at ℃ 10-2 om/m, test method is JIS-
The sealant was prepared by uniformly dissolving and mixing 10 parts by weight of spherical silicone resin fine powder (average particle size 2 μm) in 90 parts by weight (according to A-2207). When actually applying or filling this sealant to a predetermined area, it is necessary to apply or fill it at a temperature of 60°C or lower so that the synthetic resin tear sealing roll 3 does not soften, so the purpose is to increase the fluidity of the sealant. Then, 1 part by weight of the above mixture was uniformly dissolved and mixed in 2 parts by weight of an organic solvent such as toluene or a mixture of toluene and petroleum benzene, and after coating or filling, only the organic solvent was evaporated and dried.

If the above-mentioned filling is filled without any gaps into the portion 7 where the synthetic resin sealing ring 3 and the battery case 2 face each other, and the portion 7' where the sealing ring 3 and the sealing plate 1 face each other, this filling will be sealed. Since it has extremely good adhesion to the ring 3, battery case 2, and sealing plate 1, and does not dissolve in the electrolyte, the airtightness of the sealing portion is sufficiently maintained. Therefore, the leakage resistance of the electrolyte is greatly improved, and since the electrolyte does not dissipate during storage, the storage performance is also greatly improved.

Next, a comparison of the discharge performance after storage of the flat non-aqueous electrolyte battery B with a sealed structure using the sealant of the present invention described above and the same type battery B using conventional polyisobutylene as the sealant, and A comparison of leakage resistance performance is shown in Tables 1 and 2. Both of the 0mm and B batteries, each with an outer diameter of 23.0 m/m and a total height of 2.0 m/m, were also tested.

However, the discharge performance was shown by the cumulative average discharge duration until the voltage dropped to 2.4V when continuous discharge was performed at a temperature of 20° C. with a load of 30Ω connected.

Regarding leakage resistance, (1) the number of leaking batteries after being left at 45°C for 100 days, (2) the number of leaking batteries after being left at 60'C for 100 days, and (3) high temperature (60'C) and low temperature. (
-10'C) and no cycle test (MID, 5TD20
2D-1oec) for 10 days and after being left at room temperature for 90 days. It can be similarly applied to the sealing portion of the cylindrical non-aqueous electrolyte battery shown in FIG. 4 and the assembled non-aqueous electrolyte battery shown in FIG. 6.

In the cylindrical battery shown in FIG. 4, there is a space between the battery case 1a, which also serves as a negative electrode terminal, and a disc-shaped resin sealing plate 3a, and an aluminum rivet 21L, which is the internal terminal of the positive electrode, which is crimped and fixed to this sealing plate. The positive electrode terminal 2b is fixed on the caulking stud 2a with a sealant 9IL interposed between the two.

In addition, the assembled battery shown in FIG. 5 includes a long and slender cylindrical battery case 2 which also serves as a positive terminal, and a sleeve-shaped insulating sealing body 3 made of synthetic rubber.
A sealant 91L is interposed between the sealing member b and the negative electrode current collector rod 1' forming the negative electrode terminal.

Even with these structures, like the flat battery described above,
Provides excellent leakage resistance and storage performance.

Effects of the Invention As is clear from the above embodiments, the present invention provides a flat non-aqueous electrolyte battery in which a synthetic resin sealing ring and a battery case face each other, and a sealing ring and a sealing plate face each other in a part where a synthetic resin sealing ring and a battery case face each other. , which is mainly composed of pitch and mixed with 5 to 20% by weight of spherical silicone resin fine powder, has extremely good adhesion to metals, etc., and has a sealant interposed therein which does not dissolve in the organic electrolyte. Therefore, the airtightness of the battery was maintained well, and leakage of the electrolyte solution was prevented, and the storage performance and leakage resistance performance were greatly improved.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a flat non-aqueous electrolyte battery according to an embodiment of the present invention, Fig. 2 is an enlarged cross-sectional view of the human part of Fig. 1, and Fig. 3 is a spherical silicone resin microstructure with respect to the pitch of the sealant. A diagram showing the relationship between powder blending ratio and battery leakage rate. FIG. 4 is a half-cut side view of a cylindrical non-aqueous electrolyte battery according to another embodiment of the present invention. FIG. 01 is a half-cut side view of a water electrolyte battery. A sealing plate that also serves as a negative electrode terminal, 1a.
...Battery case that also serves as negative terminal, 1'...
・・Negative terminal and current collector rod, 2 ・・Battery case that also serves as positive terminal, 21L ・・Clinching stud, 2b ・・
...Positive terminal, 3...Insulating sealing ring, 3
1... Sealing plate, 3b... Sleeve-shaped sealing body, 4... Positive electrode mixture, 5... Negative electrode,
6...Separator, 8...Nonaqueous electrolyte, 9a...Sealant. ! -110 boards with negative reviews 2 - Positive electrode notes 3 and battery case 3 - Rectangle edition! 10 Risibu 4 - Positive electrode mixture 5 - Negative electrode 6 - Palator 1 Figure 8 - Rinsing well water 7 - Adding to synthetic resin Rolling 3 4 0' / Ka C) ~ N
Kame Ward...

Claims (4)

[Claims] (1) A non-contact material characterized by interposing a sealing agent consisting mainly of pitch and mixed with 5 to 20% by weight of spherical silicone resin fine powder between the terminal member and the insulating sealing member. Water electrolyte battery. (2) The sealant is applied between the insulating sealing ring and the dish-shaped battery case that also serves as a terminal for one of the positive or negative poles, and between the shallow dish-shaped sealing plate that also serves as the terminal for the other pole and the insulating sealing ring. The non-aqueous electrolyte battery according to claim 1, which is interposed between the two. (3) The sealant is applied between the can-shaped battery case and the insulating sealing plate, which also serves as a terminal for one of the positive and negative poles, and between the insulating sealing plate and the other terminal, which is the other terminal, which is caulked to the insulating sealing plate. The non-aqueous electrolyte battery according to claim 1, which is interposed between the two. (4) The sealant is between a slender cylindrical battery case that also serves as a terminal for one of the positive and negative poles and a sleeve-shaped insulating sealing body,
2. The non-aqueous electrolyte battery according to claim 1, wherein the current collecting rod, which also serves as the other electrode terminal, is interposed between the sleeve-shaped insulator and the other electrode terminal.